Ok, a couple of notes from reading through the recipe sheets and the score cards. I don't have Bokonon's entries so the summary is a little incomplete.
The good:
They were all very good examples of a westvleteren 12 style quadrupel. Aside from one flat one and one that didn't seem to carb up well they were without serious flaws.
The bad:
The differences aren't significantly pronounced and peoples entries are similar enough you could write all the variation between #1 and #8 to the brewers personal influences and minor things like water profile, fermentation temperature and sugar recipe.
What we learned
Aroma
Not much to say here as everyones beer (even the flat ones didn't do too bad) had some great aromas. If anything the Westvleteren was par for the course. I think the recipe is pretty hard to do wrong (barring defects/infections) in the aroma department. ALL of them had some complex malts with significant and wonderful cocoa notes. Lots had some dried/candied red/brown fruit, and some had a nice candied/burnt banana. Two had some vegetal/bean-ish notes which weren't bad, as the Westvleteren actually had this character as well. Not sure what causes this, but I think everyone did well here.
Appearance
Color
Most of the entries were lighter than the real thing. As I suspected 80 SRM is insufficient, even with putting all 3lbs of candi sugar in at the beginning of the boil. I believe my 3rd batch (which went into the Cuvee de Tomme project) was nearly spot on and that had 3lbs of 160 SRM D2 sugar. My New World recipe (26 srm) was close but still a bit lighter. One of Bokonon's entries (probably new world) was darker than mine and really close to the darkness of the real thing. If you want to come close to the "real thing" shoot for 30-32 SRM minimum.
However, they were all MORE THAN sufficiently dark for entry as a 18E and I didn't feel that any of them were too light. Your personal preference here.
Clarity
We ran the gamut here, some hazy entries, some fairly clear entries and two nearly brilliant entries and nobody used finings. The real thing was pretty clear despite is considerably dark color. Only the really hazy ones probably got a ding for being too hazy, but they didn't get dinged as badly as ones with carbonation problems.
Carbonation
For the most part everyone scored perfect here aside from two with issues. The real thing was fairly inline with those that entered beers as 2.8-3 vol/CO2. Interestingly my New World I did at 2.6 vol/co2 and it did well enough
Flavor
Bitterness
This varied little and more or less close enough. That being said a lot of the entries were 4-5 months old at this point. If you want it drinkable younger maybe cut the bitterness down to about 30-32 IBU. Again your personal preference.
Interesting note: A few people had 120 minute boils & hop additions for their traditional and KingBrianI had a 60 minute hop addition. I don't think it mattered at all.
Hoppiness
This style is not supposed to have any real noticable hop characters and nobodies did. Whats interesting about this is that KingBrianI had some 15 and 0 minute hop additions whereas most other people's last hop additions were 25-45. Again giving it 4-5 months and the low IBUs is going to render this aspect moot. You could make your brewday easier by having less additions, maybe not even bothering with finishing hops.
Overall Flavor
Some were a little lighter in malt flavor/biscuit/bread but none got too heavy, I think the amount of sugar is part of the deal here. We ranged from 12-19% of the gravity from sugar, though its hard to just look and see what peoples efficiencies were. Some very un-scientific measurements based on the data we have makes me think somewhere in the middle is a nice balance of malt/sugar flavors and body. A good number of the beers were similar to Westvleteren, with some with more malt/body and some with less malt/body. I think 14-16% is a good target, and you can probably get away with more sugar if you do a big decoction on a traditional recipe.
All had a good amount of esters (within style) but some were a little less than Westvleteren and I think one got dinged for being "too clean". On the recipe sheets I'm also noticing a near correlation in lower fermentation temperatures with reduced esters comments. First place had a fermentation temp of 82, second place had a fermentation temp of 84, and third place had a fermentation temp of 81. A lot of others only got to 80. I think this aspect is pretty important and 82-84f is probably the ideal target.
As with the aroma, all of the beers had a very significant nice cocoa note.
Mouthfeel
As mentioned in the Overall Flavor aspect, some were a little lighter in body and richness than Westvleteren 12, but were well represented for the style . However none of them were cloyingly sweet nor too dry and fairly well balanced overall. Hard to say here as the grainbills and proportions are all fairly similar. Given that a new world recipe did so well against so many traditionals I think that some residual body from the grain must be at play, large decoctions will help this aspect but must be balanced with the amount of sugar.
Overall
Overall this was a really good competition and project, with most people's scores being 38 or higher which is "Excellent" by the BJCP. I think everyone that participated and didn't have issues have beers that are worthy of any competition, and the ones that did have issues were fairly minor and could be easily fixed.
My takeaway from this is that both the new world and traditional recipes can get pretty damn close! I am glad I decided to do a new world recipe as I feel it provided valuable input for judging, but will probably continue to brew the traditional recipe in the future. When I do The Pious #3 (last one didn't count because it went into the bourbon barrel for souring right away) I will go with the same recipe I have posted in the other Westvleteren thread but adjust the sugar to 15% of grist.